This invention relates to a thin and flat keyboard structure.
As disclosed in earlier applications Nos. 16,075 on Feb. 28, 1979 and 33,414 on Apr. 14, 1979 both entitled METALIC HOUSING FOR AN ELECTRONIC APPARATUS WITH A FLAT KEYBOARD, the applicant of this application has proposed a new type of a keyboard which takes advantage of part of an upper member of a housing as key actuators or key tops. Cutouts are each formed around the whole periphery of a respective one of limited areas of a housing member except for a hinge section, the respective limited areas defined by the cutouts behaving as the key actuators. Since the housing member and the key actuators are both made from the same material and it is difficult to work the key actuators independently of the housing member, the above mentioned attempts are still unsatisfactory in that neither distinction between the key actuators and the housing member nor the positions of the key actuators itself are ambiguous and an objectionable gap occurs between the housing member and the key actuators, thus presenting the possibility that the edges of the key actuators may be scratched by the operator's finger and sometimes become warped in the upward direction. The suggested keyboard in which the hinge sections remain is of a practical advantage in that the key actuators may be integral with the housing member but has difficulty in obtaining an appropriate key load in view of the necessary strength of the housing, etc.
Accordingly, it is an object of the present invention to provide an improvement in the earlier filed keyboards in which two metallic sheets with a very thin thickness are employed to constitute an upper member of the housing and the key actuators.